The present invention relates to the document duplication arts. It finds particular application in conjunction with dual sided photocopiers, and will be described with particular reference thereto. However, it is to be appreciated that the present invention is also amenable to other like applications.
Office equipment, such as printers and copiers, which place images based on digital data onto sheets, such as sheets of paper, are well known. More sophisticated types of office equipment are capable of placing images on both sides of a single sheet of paper, a feature often referred to as xe2x80x9cduplexing.xe2x80x9d A typical configuration of a duplexing printer (the word xe2x80x9cprinterxe2x80x9d including other types of equipment, such as digital copiers and facsimile machines) includes an image rendering device, meaning some hardware/software component that places a desired image on a sheet. Such a device is physically capable of printing only on one side of the sheet at a time. In order to print on both sides of the same sheet, it is necessary to feed a sheet through the image rendering device so the sheet can receive a first image on one side, and then invert the sheet and re-feed it back into the image rendering device so that the image rendering device can place a second image on the other side of the sheet. Although the specific architectures of various office equipment on the market vary widely, the path (along with any associated sheet-handling hardware, such as belts or rollers and motors) by which a sheet which has been output by the image rendering device is inverted and re-fed to the image rendering device can be generally referred to as a xe2x80x9cduplex path.xe2x80x9d
In the market for office equipment having duplex features, a common customer requirement is a precise registration between an image printed on one side of the sheet with the image printed on the other side. If a single sheet having images on both sides thereof is held up to the light, it is desirable that the margins of the two images, particularly if the images include text, be perfectly superimposed. There is therefore a need to provide a system by which the image placed on one side of a sheet by the image rendering device is registered with the image on the other side of the sheet.
In other applications, it may be desirable to register the second side image to the page upon which it is printed, disregarding any image that may be printed on the first side. In an environment where the user may need to alternate between registering schemes, it is desirable to give the user control of how the images on the second side are registered.
Typically, in image registration, the image is not registered on a per page basis. That is, a registration processor does not receive a reading of a location of the instant page and adjust an image rendering device solely for that page. In some sophisticated devices, a running average of page position is taken and the instant page is typically registered based on that average. Depending on factors such as job length, acceptable misregistration, and others, different numbers of pages will be averaged for registration of subsequent pages. This can apply to both sides one and two. It is desirable to give the user control over the amount of pages used in the averaging scheme for registration depending on the job specifications.
The present invention contemplates a new and improved method and apparatus, which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, a document duplication apparatus is provided. The apparatus includes an image rendering device for affixing images to documents. First and second paths include first and second sensors, respectively. The sensors detect the position of the document. A controller controls positioning of the image rendering device based on information from the first and second sensors. A user interface allows a user to select between image-to-image and image-to-page registration.
In accordance with another aspect of the present invention, a document duplication apparatus is provided. The apparatus includes a feed path, the path having a sensor. An image placement controller registers an image rendering device based on a running average of positions of previous documents. A user interface allows a user to set a number of documents over which the running average is calculated.
In accordance with another aspect of the present invention, a method of image registration is provided. A document is fed along a feed path and an image rendering device is registered thereto with respect to an edge of the document. An image is affixed to the first side. The document is fed along a duplex path and the image rendering device is registered to the document again, with respect to a number of prior document positions. An image is affixed to the second side. A registration option for the second side image is selected, and a number of prior document positions from which to average is selected.
In accordance with another aspect of the present invention, a document duplication apparatus is provided. The apparatus includes feed and duplex paths, the duplex path having a sensor, the sensor detecting a position of the page. An image placement controller registers an image rendering device based on a running average of positions involving previous documents. A user interface allows a user to set the number of previous documents used for averaging and choose between registration relative to the side one image and registration to the page.
One advantage of the present invention resides in the ability to control a number of prints over which a running average is taken for side one and side two.
Another advantage of the present invention resides in the ability to control whether a side two image is registered with reference to a side one image or the page upon which it is printed.
Another advantage of the present advantage is the ability to make a tradeoff between system recovery and accuracy of image placement for both side one and side two.
Another advantage of the present invention resides in the ability to adjust print settings based on job parameters.
Still further advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.